Degradation of diiodoacetamide in water by UV/chlorination: Kinetics, efficiency, influence factors and toxicity evaluation

Zhi Liu; Yi-Li Lin; Bin Xu; Chen-Yan Hu; Tian-Yang Zhang; Tong-Cheng Cao; Yang Pan; Nai-Yun Gao

doi:10.1016/j.chemosphere.2019.124761

Degradation of diiodoacetamide in water by UV/chlorination: Kinetics, efficiency, influence factors and toxicity evaluation

Chemosphere. 2020 Feb:240:124761. doi: 10.1016/j.chemosphere.2019.124761. Epub 2019 Sep 10.

Authors

Zhi Liu¹, Yi-Li Lin², Bin Xu¹, Chen-Yan Hu³, Tian-Yang Zhang⁴, Tong-Cheng Cao⁵, Yang Pan⁶, Nai-Yun Gao⁷

Affiliations

¹ State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, PR China.
² Department of Safety, Health and Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung, 824, Taiwan, ROC.
³ Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, PR China; College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai, 200090, PR China.
⁴ State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, PR China. Electronic address: tianyang1815@126.com.
⁵ School of Chemical Science and Engineering, Tongji University, Shanghai, 200092, PR China.
⁶ State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China.
⁷ State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, PR China.

PMID: 31546190
DOI: 10.1016/j.chemosphere.2019.124761

Abstract

The formation and control of haloacetamides (HAcAms) in drinking water have raised high attention due to their high genotoxicity and cytotoxicity, especially the most cytotoxic one, diiodoacetamide (DIAcAm). In this study, the degradation of DIAcAm by UV/chlorination was investigated in terms of degradation kinetics, efficiency, influencing factors, oxidation products and toxicity evaluation. Results revealed that the degradation of DIAcAm by UV/chlorine process followed pseudo-first-order kinetics, and the rate constant between DIAcAm and OH radicals was determined as 2.8 × 10⁹ M^-1 s^-1. The contribution of Cl to DIAcAm degradation by UV/chlorine oxidation was negligible. Increasing chlorine dosage and decreasing pH significantly promoted the DIAcAm degradation during UV/chlorine oxidation, but the presence of bicarbonate (HCO₃^-) and natural organic matter (NOM) inhibited it. The mass balance analysis of iodine species was also evaluated during UV/chlorine oxidation of DIAcAm. In this process, with DIAcAm decreasing from 16.0 to 0.8 μM-I in 20 min, IO₃^-, I^- and HOI/I₂ increased from 0 to 6.3, 6.1 and 0.5 μM-I, respectively. The increase of CHO cell viability during DIAcAm degradation indicated that the toxicity of DIAcAm could be decreased by chlorination, UV irradiation and UV/chlorine oxidation treatments, in which UV/chlorine oxidation was more effective on toxicity reduction than chlorination and UV irradiation alone.

Keywords: Degradation; Diiodoacetamide; Kinetics; Toxicity; UV/chlorine oxidation; Water treatment.

MeSH terms

Acetamides / chemistry*
Chlorine / analysis
Halogenation
Kinetics
Oxidation-Reduction
Ultraviolet Rays
Water
Water Pollutants, Chemical / analysis
Water Pollutants, Chemical / chemistry*
Water Pollutants, Chemical / toxicity
Water Purification / methods

Substances

Acetamides
Water Pollutants, Chemical
Water
Chlorine